1. Field of the Invention
The present invention relates to a process and apparatus for growing compound semiconductor monocrystal by reduced epitaxial growth in an open-pipe process.
2. Description of the Prior Art
Gaseous phase growing methods for a compound semiconductor, for example, GaAs which is one of typical elements, so far known include chloride method, hydride method, organic metal gaseous phase growing method (MO-CVD method) and the like.
Both the chloride method and hydride method are methods not to feed gaseous components containing Ga from the exterior of a reaction pipe but normally to feed AsCl.sub.3 and HCl with H.sub.2 gas as a carrier gas into a reaction pipe to react with Ga within the reaction pipe and feed chloride of Ga onto the base plate to grow GaAs monocrystal.
However, both the chloride method and hydride method have the disadvantages that it is difficult to simultaneously vary a ratio between a gas component containing Ga and a gas component containing As and difficult to control the stoichiometry of GaAs crystal.
On the other hand, according to the MO-CVD method, an organic metal is used for a Ga source, and therefore, it is possible to simultaneously vary a ratio between a gas component containing Ga and a gas component containing As, as a result of which the MO-CVD method has an advantage that stoichiometry may be controlled but has a disadvantage in that the quality of crystal is inferior to that of the chloride method and hydride method.